In axial flow rotary machines, rotor assemblies are driven at high rotational speeds about an axis of rotation. The rotor assemblies include rotor disks and rotor blades. Foreign objects, such as birds, hailstones or other objects, which on occasion are ingested into the engine may strike the blades causing parts of the rotor assembly to fragment or to separate from the rotor disk. During such a failure pieces of the rotor assembly may be hurled outwardly from the rotor assembly with velocities of several hundred feet per second. Such velocities typically have components in the axial, tangential and radial directions. One device for containing such fragments is shown in British Patent Specification No. 1,245,415 issued to Mottram et al entitled "Improvements in or Relating to Fluid Flow Machines". Mottram shows a containment structure formed of two similar metal strip members wound together to form a helical shield. The shield is wound about a solid casing. U.S. Pat. No. 2,999,667 entitled "Protective Arrangement for Use with Apparatus or Machines Having Rotating Parts" issued to Morley shows a containment structure formed of a web of interwoven wires which are continuous from one end of the web to the other. The web is supported in coil form in a first casing between an inner wall and a slidable outer wall. A second casing is spaced radially inwardly from the first casing and extends circumferentially about an array or rotor blades.
Several patents show containment structures formed from synthetic fibers which are woven into a fabric or webbing. U.S. Pat. No. 4,057,359 entitled "Ballistic Nylon Fabric Turbine Governor Housing Shielding Means" issued to Grooman shows a flexible housing cover formed by stitching together two sections of a ballistic nylon fabric. The cover fits over the housing and is held in place by a removable band. U.S. Pat. No. 3,602,602 issued to Motta entitled "Burst Containment Means" shows a containment means formed of a winding of tape over a machinery housing and aligned with the expected path of travel of part fragments to contain the part fragments during a failure of the rotary machine. The cross-sectional view of the housing shows a solid housing. A contemporaneous recommendation for a containment structure appears in a NASA Final Report entitled "Development of Advanced Lightweight Containment Systems". This report was made under NASA Contract No. NAS3-21823. The containment structure includes a honeycomb backed steel shell, a fabric extending circumferentially about the shell and felt material trapped radially between the fabric and a honeycomb backed steel shell.
In spite of this progress in containment structures, scientists and engineers are seeking to develop an apparatus for positioning a fabric containment means for containing particles released from an array of rotor blades.